git: 43a03be0bb50 - stable/12 - snd_uaudio(4): Fix string index computations for iFeature.

The branch stable/12 has been updated by hselasky:

URL: https://cgit.FreeBSD.org/src/commit/?id=43a03be0bb5070b445b1c16d17b1791d345ec5d0

commit 43a03be0bb5070b445b1c16d17b1791d345ec5d0
Author:     Hans Petter Selasky <hselasky@FreeBSD.org>
AuthorDate: 2021-11-09 21:07:36 +0000
Commit:     Hans Petter Selasky <hselasky@FreeBSD.org>
CommitDate: 2021-11-16 08:10:42 +0000

    snd_uaudio(4): Fix string index computations for iFeature.
    
    This allows the iFeature strings to be properly read by the snd_uaudio(4) driver,
    when parsing the audio feature unit descriptors.
    
    Submitted by:   Zhichao1.Li@dell.com
    Sponsored by:   NVIDIA Networking
    
    (cherry picked from commit 11f09b17fe2cf0b5489601aee548a06486f0b749)
---
 sys/dev/sound/usb/uaudio.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/sys/dev/sound/usb/uaudio.c b/sys/dev/sound/usb/uaudio.c
index 221f4d3d1bd7..d620d5fd1cce 100644
--- a/sys/dev/sound/usb/uaudio.c
+++ b/sys/dev/sound/usb/uaudio.c
@@ -3666,18 +3666,18 @@ uaudio_mixer_add_feature(struct uaudio_softc *sc,
 		cmask |= uaudio_mixer_feature_get_bmaControls(d, chan);
 	}
 
-	if (nchan > MIX_MAX_CHAN)
-		nchan = MIX_MAX_CHAN;
-
 	MIX(sc).wIndex = MAKE_WORD(d->bUnitId, sc->sc_mixer_iface_no);
 
-	i = d->bmaControls[d->bControlSize];
+	i = d->bmaControls[nchan * d->bControlSize];
 	if (i == 0 ||
 	    usbd_req_get_string_any(sc->sc_udev, NULL,
 	    MIX(sc).desc, sizeof(MIX(sc).desc), i) != 0) {
 		MIX(sc).desc[0] = 0;
 	}
 
+	if (nchan > MIX_MAX_CHAN)
+		nchan = MIX_MAX_CHAN;
+
 	for (ctl = 1; ctl <= LOUDNESS_CONTROL; ctl++) {
 
 		fumask = FU_MASK(ctl);
@@ -3801,9 +3801,6 @@ uaudio20_mixer_add_feature(struct uaudio_softc *sc,
 	for (chan = 1; chan < nchan; chan++)
 		cmask |= UGETDW(d->bmaControls[chan]);
 
-	if (nchan > MIX_MAX_CHAN)
-		nchan = MIX_MAX_CHAN;
-
 	MIX(sc).wIndex = MAKE_WORD(d->bUnitId, sc->sc_mixer_iface_no);
 
 	i = d->bmaControls[nchan][0];
@@ -3813,6 +3810,9 @@ uaudio20_mixer_add_feature(struct uaudio_softc *sc,
 		MIX(sc).desc[0] = 0;
 	}
 
+	if (nchan > MIX_MAX_CHAN)
+		nchan = MIX_MAX_CHAN;
+
 	for (ctl = 3; ctl != 0; ctl <<= 2) {
 
 		mixernumber = uaudio20_mixer_determine_class(&iot[id]);